Many applications require thermal insulation of devices or components so as to protect these devices or components from damage and ensure their operating ability.
One example of thermally insulating means includes multi-layer insulation (MLI) blankets. MLI blankets are in particular capable of reducing thermal energy exchange by thermal radiation. MLI blankets generally comprise multiple dielectric and electrically conductive layers. Dielectric layers may for instance be formed by a dielectric substrate, e.g. a polyimide and/or polyester substrate. Conductive layers may for instance be formed by a conductive coating, e.g. a metal coating, such as aluminum or a silver coating for instance, on one side of a dielectric substrate or on both sides thereof. At least some of the layers mainly act as radiation-heat transfer barriers. Between the radiation-heat transfer barriers, thermally insulating spacers may be provided. An example of such a spacer is a scrim. An external layer of an MLI blanket may form an inner cover on one side of the internal layers of the MLI blanket and another external layer of the MLI blanket may form an outer cover on the opposite side of the MLI blanket, the inner cover and the outer cover thus covering the internal layers of the MLI blanket. The inner cover may refer to the cover of the MLI blanket that is configured to face a structure on which the MLI blanket is mounted.
Spacecraft, e.g. satellites, are a common field of application of MLI blankets, where the MLI blankets provide protection against both extreme heat and cold. In this field of application, the inner cover of an MLI blanket mounted on the spacecraft faces the spacecraft structure and the outer cover is configured to face space.
EP 2 530 366 A1 and FR 2 976 044 A1, for instance, disclose MLI blankets.
Electrical discharge may cause harm to a device or component thermally shielded by an MLI blanket. So as to prevent electric charge from accumulating and then, at some point, discharging, grounding of the MLI blanket, specifically of its conductive layers, is required. For spacecraft, regulations exist that require MLI blankets to be grounded.
Improvements in MLI blanket grounding are desirable.